Force PATTERN to match only whole words.  A "whole word" is a
substring which either starts at the beginning or the record or is
preceded by a non-word constituent character.  Similarly, the
substring must either end at the end of the record or be followed by a
non-word constituent character.  Word-constituent characters are
alphanumerics (as defined by the current locale) and the underscore
character.  Note that the non-word constituent characters must
surround the match; they cannot be counted as errors.

Set cost of incorrect characters to NUM.  Note that a deletion (a
missing character) and an insertion (an extra character) together
constitute a substituted character, but the cost will be the that of a
deletion and an insertion added together.  Thus, if the const of a
substitution is set to be larger than the sum of the costs of deletion
and insertion, direct substitutions will never be done.

Set the record delimiter regular expression to PATTERN.  The text
between two delimiters, before the first delimiter, and after the last
delimiter is considered to be a record.  The default record delimiter
is the regexp "\n", so by default a record is a line.  PATTERN can be
any regular expression that does not match the empty string.  For
example, using -d "^From " defines mail messages as records in a
Mailbox format file.